busybox: remove validation message from bootup

A message:
uinteger - 9 = true
is displayed during boot. This is the result of the validate_data
command checking the cron log level. As the output is not
interesting, only the result, filter...

Signed-off-by: Michel Stam <m.stam@fugro.nl>
git-svn-id: svn://svn.openwrt.org/openwrt/trunk@42751 3c298f89-4303-0410-b956-a3cf2f4a3e73